Anonymous Coward wrote on 2020-08-19, 14:25:

Apparently the ATI Graphics Solution cards support an extended plantronics mode that does 640x200x16. Is there any chance to support the Sierra EGA/VGA games that use EGA 640x200x16 to emulate 256 colours?

While I'm quite familiar with both, programming the Graphics Solution's 640x200x16 mode and 256 color emulation using pixel pairs from my work on an unreleased Planet X3 port, an SCI driver for this mode doesn't have the highest priority, right now.
The biggest obstacle by far is that no emulator supports the mode, combined with the fact that my turbo XT does not have a hard drive.

But I have thought about adapting the Plantronics driver for 256-color input and output in 16 shades of gray via composite or 15kHz TTL monochrome screen.

The LUT-based speed optimizations that I applied to the PCPLUS driver a couple of days ago have a funny side effect:
They cause King's Quest I SCI to run slower than before.

Apparently, the engine benchmarks the video driver and enables additional effects like water waves and flying birds when the driver is faster than a certain threshold.
I had to switch the PCem VM from a 12MHz 8088 to a 10MHz 8088 to make it playable, again.
The cursor drawing code, on the other hand, is still painfully slow, because it has not been optimized, yet.

By the way:
There are quite a few Plantronics compatible cards floating around in the bay, right now, including ATI Graphics Solutions, HEGAs, a Winbond 6190 card and a few others where I'm not quite sure.
Your best bet is to just search for 8-bit ISA video cards and to scroll through, because most sellers don't even know what they are selling.

Benedikt wrote on 2020-08-21, 20:08:

Apparently, the engine benchmarks the video driver and enables additional effects like water waves and flying birds when the driver is faster than a certain threshold.
I had to switch the PCem VM from a 12MHz 8088 to a 10MHz 8088 to make it playable, again.
The cursor drawing code, on the other hand, is still painfully slow, because it has not been optimized, yet.

Yeah, I noticed the effects of that built-in benchmark as well, back in the day. After replacing the 8MHz 8086 CPU in an Olivetti M24 with a NEC V30 at the same clockspeed, I noticed some extra animations being enabled in Space Quest III. SCUMM games apparently had a similar built-in benchmark, with about the same performance threshold. In the <=16-color version of Monkey Island 1, after the V30 upgrade, I would suddenly see a pirate swinging back and forth in the chandelier in the main room of the SCUMM Bar.

digger wrote on 2020-08-21, 20:34:

Benedikt wrote on 2020-08-21, 20:08:

Apparently, the engine benchmarks the video driver and enables additional effects like water waves and flying birds when the driver is faster than a certain threshold.
I had to switch the PCem VM from a 12MHz 8088 to a 10MHz 8088 to make it playable, again.
The cursor drawing code, on the other hand, is still painfully slow, because it has not been optimized, yet.

Yeah, I noticed the effects of that built-in benchmark as well, back in the day. After replacing the 8MHz 8086 CPU in an Olivetti M24 with a NEC V30 at the same clockspeed, I noticed some extra animations being enabled in Space Quest III. SCUMM games apparently had a similar built-in benchmark, with about the same performance threshold. In the <=16-color version of Monkey Island 1, after the V30 upgrade, I would suddenly see a pirate swinging back and forth in the chandelier in the main room of the SCUMM Bar.

That is an interesting observation. Are you aware of any way to manually disable the additional effects. When the system performance is right at the threshold, they can be quite annoying.

Benedikt wrote on 2020-08-22, 11:18:

That is an interesting observation. Are you aware of any way to manually disable the additional effects. When the system performance is right at the threshold, they can be quite annoying.

That's understandable, but unfortunately I'm not aware of any way of disabling (or enabling) such additional effects manually. As far as I remember, there was no "detail slider" in the settings or anything, at least not in SCI and SCUMM games. There might be some undocumented command-line parameter for that in these games, but I don't know of of any. Maybe some googling or opening the EXE with a hex viewer might yield some insights in that regard.

By the way, there are quite a few different ways in which such a built-in benchmarking routines might work. Such a software mechanism might not just be doing a speed test. For instance, it could also be checking for the support of certain instructions that 8086 and 8088 CPUs don't support. The V20 and V30 CPUs supported a number of additional 286 instructions, so that might result in the enabling of certain more demanding animations that were intended only for 286+ systems.

My Schneider EuroPC has a Paradise PVC4. Does this driver help me getting more out of the standard gfx? (MDA or CGA) ?

Yes, namely the 320x200 16-color mode on a CGA screen. You'd be the first one to test it on such a machine, but I don't expect any hiccups.

There is a list of known-working games in one of my earlier posts.

today I have tested the compatible games with the 2 ati cga cards I own , everything worked fine - I have not played through any game but I doubt there will be any issue

nice work Benedikt! 😀

That's amazing news!

And this is a screenshot of the King's Quest IV (SCI) Demo displayed on a Commodore 1084 screen via ATI "Small Wonder" Graphics Solution v.1:

It is updating the screen surprisingly fast, as well. The machine is a double-speed turbo XT (PC 20-III).

This is sooo cool! How did you wire up the 1084? That would make for an awesome CGA monitor.

I wired it up with a DE9 to circular 8-pin DIN cable to its digital RGBI input. More accurately, I took a serial cable and replaced one of the plugs.
The 1084 is actually the CGA monitor recommended in the PC 20-III's manual.

Nice. I want a card! 😀 But maybe it’s easier to just use my EGA card and tell it that it’s hooked up to a CGA monitor.
My 1084S is a D2 (I think) with DB9 socket. So I think I could use a serial (straight wired) cable.

There are listings for compatible cards out there, but the prices asked are a bit high.
Your EGA card was an EGA Wonder 800+, right? Its CGA screen detection checks for the presence of two GND connections.
If your screen wires both, pin 1 and pin 2 to GND, the card should be able to auto-detect it as CGA screen.

Back to the driver: My experience yesterday might have been as good as it was, because I had no mouse connected. Mouse cursor optimizations are still pending.

Awesome work!

I'm surprised the Plantronics standard had virtually no support, not in games, not even in paint programs and image viewers. I know the original full-length ISA card was never a big seller and out of date by the mid 80s, but the standard was was fairly common later on as some Commodore, Packard Bell and Amstrad PCs had it implemented on the motherboard and the ATI Small Wonder was a pretty common video card at the time.

I can only assume that the mode itself went largely unnoticed and that not only game developers, but even the system owners themselves often did not know about it.
In other words: Bad marketing all around!
Budget PC manufacturers could have used this kind of driver to boost their sales, but didn't.
There is no compelling reason why this driver could not have been written 30 years ago.

yeah this was a wasted opportunity... 16colors ega-like games/apps on cga system? everyone would want that

Absolutely. In my memory it is imprinted that CGA sucked, especially in Europe where the color artifacting wasn't a thing. Having support for 16 color CGA in shareware or commercial games would have changed that. Even EGA games usually only used the CGA palette anyway, since the lowest common denominator was EGA and a CGA monitor. So supporting a 16 color CGA card would have made perfect sense. 11 year old me is sad...

Perhaps it is a case of video game developers and publishers not understanding how commonplace these CGA+ cards actually were. In those days, IBM still dominated the industry, and they set the standards.

The one exception to that was Hercules monochrome graphics, which took off because IBM basically left a huge gap in demand for others to fill when they neglected to include a bitmapped graphics mode in the MDA card.

Even the Tandy 16 color mode was designed to be compatible with the IBM PCjr, which introduced that mode first. And as far as IBM was concerned, there was nothing between CGA and EGA.

And then again, maybe in hindsight we are overestimating the actual total marketshare that PC clones with these 16 color CGA+ cards actually had, and software developers didn't believe it was worth the effort. Their games would still work fine in 4 color CGA mode with those cards, right? Let them play it like that, they probably thought. 😕

Perhaps it was also a matter of the marketshare in Europe vs the marketshare in North America, where most of the games were developed? Wasn't the Tandy 1000 much more commonplace there, whereas it may have been mostly European PC clones such as Schneider, Philips/HeadStart and Tulip, that had graphics cards that supported this mode? I'm just speculating here, though.

I think that while the original Plantronics ColorPlus card came very early, somewhat widespread support in budget PCs wasn't a thing until the mid to late 80s, in other words until the gaming industry had largely moved on to EGA and the Amiga.
Another important factor is speed: While EGA can be twice as fast as CGA, the Plantronics mode is twice as slow. Maybe too slow on what is already a budget PC.

An SCI driver, however, would still have been an option, because a double-speed XT is evidently fast enough, even with a driver that has not been brutally optimized for speed.
By the way: I have added mouse cursor optimizations!